ou work in a company which is named Wiikigo Corp. The company uses SQL Server 2008. You are the administrator of the company database. Now for a new application, a SQL Server 2008 instance has to be installed on an existing server. The server contains a default SQL Server 2005 instance. Your company CIO wants their corresponding certified third-party applications can access to both database instances. The company assigns this task to you. You must achieve this by using as little database administrative effort as possible, and never change the existing application environments. What should you do? （） 

• A、You should install SQL Server 2008 as the default instance, and configure the new application to use the default instance 
• B、You should upgrade the SQL Server 2005 application to use SQL Server 2008 
• C、You should upgrade the SQL Server 2005 instance to a SQL Server 2008 instance 
• D、You should install SQL Server 2008 as a named instance, and make the new application use the new instance.